System and method for forming material substrate printer

ABSTRACT

A method is disclosed for manufacturing a part via an additive manufacturing process. A solution is used which has a volatile component within which is suspended particles of a powdered material. The solution is heated until it at least one of begins boiling or is about to begin boiling. The heated solution is then deposited at least at one location on a substrate to help form a layer of the part. The volatile component then evaporates, leaving only the particles of powdered material. The particles are then heated to the melting point. The deposition and heating operations are repeated to successively form a plurality of layers for the part. The evaporation of the volatile component helps to cool the part.

STATEMENT OF GOVERNMENT RIGHTS

The United States Government has rights in this invention pursuant toContract No. DE-AC52-07NA27344 between the U.S. Department of Energy andLawrence Livermore National Security, LLC, for the operation of LawrenceLivermore National Laboratory.

FIELD

The present disclosure relates to additive manufacturing systems andprocesses, and more particularly to an additive manufacturing system andmethod which delivers a powdered material suspended in a solution to asurface, after which the solution evaporates leaving just the powderedmaterial, which is then melted by a heat source to form a material layerof a part.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Current powder delivery systems for additive manufacturing (“AM”)processes such as Selective Laser Sintering (“SLS”), Direct Metal LaserSintering (“DMLS”), or Diode based Additive Manufacturing use a singletype or composition of powder per part. The powder is swept over alowered part creation zone creating a layer of powder of a specifiedthickness.

As layer upon layer of material is deposited in a traditional SLS orDMLS system, the part being created grows thicker and thicker. For thefirst few initial layers of part creation, the heat delivered to meltthe material is removed by conduction to the base substrate that thepowder is initially deposited on. As the part becomes thicker andthicker, this conduction pathway becomes insufficient at removing theexcess heat in the part. As a result, the part begins to rise intemperature. The temperature of the part continues to increase assuccessive materials layers are melted, until the part eventuallyreaches a temperature which is just below the melting point of thepowder. Accordingly, cooling the part to permit the continuedapplication of material layers typically becomes a significantchallenge. Complicating this is the desire to be able to fully completethe manufacture of the part, using the AM manufacturing process, in asshort a time as possible.

Also, in traditional SLS or DMLS systems, the powder bed is filled withthe powder to be melted, as well as a portion of the powder which is notmelted. This can result in the powder bed being required to supportsignificant weight when heavy and/or dense powdered material types arebeing used.

SUMMARY

In one aspect the present disclosure relates to a method formanufacturing a part via an additive manufacturing process. The methodmay comprise forming a solution including a volatile component withinwhich is suspended a plurality of particles of a powdered material. Thesolution may be heated to a temperature at which the volatile componentat least one of begins boiling or is about to begin boiling. A materialdeposition operation may then be performed by depositing the heatedsolution at least at one location on a substrate to help form a layer ofthe part, and allowing the volatile component to evaporate, thus leavingonly the particles of powdered material at the location. A heatingoperation may then be performed using a heat source to heat theparticles of powdered material to a temperature sufficient to melt andfuse the particles of powdered material together. The materialdeposition and heating operations may be repeated to successively form aplurality of layers for the part. The evaporation of the volatilecomponent helps to cool the part.

In another aspect the present disclosure relates to a method formanufacturing a part via an additive manufacturing process. The methodmay comprise forming a first solution having a first volatile componentwithin which is suspended a first plurality of particles of powderedmaterial. A second solution may be formed which has a second volatilecomponent within which is suspended a second plurality of particles ofpowdered material. The first and second solutions may be heated totemperatures at which the first and second volatile components at leastone of begin boiling or are about to begin boiling. A materialdeposition operation may then be performed by depositing the heatedfirst and second solutions at first and second different locations on asubstrate to help form a layer of the part, and allowing the first andsecond volatile components to evaporate. This leaves only the first andsecond pluralities of particles of powdered material at the first andsecond different locations. A heating operation may then be performedusing a heat source to at least substantially simultaneously heat thefirst and second pluralities of particles of powdered material totemperatures sufficient to melt and fuse the first plurality ofparticles of powdered material together, and to fuse the secondplurality of particles of powdered material together. The materialdeposition and heating operations may be performed repeatedly tosuccessively form a plurality of layers until the part is fully formed.The evaporation of the first and second volatile components helps tocool the part.

In still another aspect the present disclosure relates to a system formanufacturing a part via an additive manufacturing process. The systemmay comprise a solution including a volatile component within which issuspended a plurality of particles of a powdered material. A processormay be included which is used to control a heat source. The heat sourceis adapted to heat the solution to a temperature at which the volatilecomponent at least one of begins boiling or is about to begin boiling. Amaterial deposition component is included which may be controlled by theprocessor. The material deposition component may deposit the heatedsolution at least at one location on a substrate to help form a layer ofthe part, and wherein the volatile component may evaporate after beingdeposited to leave only the particles of powdered material at thelocation. The processor may control the heat source to heat theparticles of powdered material to a temperature sufficient to melt andfuse the particles of powdered material together. The processor maycause additional depositing and heating operations to be repeatedlyperformed to successively form a plurality of layers for the part, andwherein the evaporation of the volatile component helps to cool the partduring formation of the part.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a high level illustration of a system in accordance with oneembodiment of the present disclosure; and

FIG. 2 is a flowchart illustrating one example of operations that may beperformed by the system of FIG. 1 in carrying out an AdditiveManufacturing (“AM”) process to manufacture a part.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, its application or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

The system and method of the present disclosure makes use of a coolingmechanism in the form of a volatile solvent. The volatile solvent actsas a carrier fluid for material particles which are deposited on asubstrate, or on a previously formed layer, during an additivemanufacturing (“AM”) process. The latent heat of vaporization of thefluid is capable of removing a great deal of heat and can effectivelycool the surface of the part where it sees the thermal heat flux, and isthe hottest.

Referring to FIG. 1, a system 10 in accordance with one embodiment ofthe present disclosure is illustrated. The system 10 may include one ormore material deposition components, in this example nozzles 12-16, thatare each able to deposit an associated solution 12 a-16 a which includesparticles, for example metallic particles, that will be melted to formsuccessive material layers one on top of another. In this example thesolutions 12 a-16 a each include different types of particles 22 a-22 c,respectively. As a result, a part made using the system 10 may be formedfrom a plurality of different types of materials. This is in contrast totraditional types of AM systems which are only able to make a part usinga single type of material.

While three nozzles 12-16 are illustrated, the system 10 is not limitedto use with any particular number of different nozzles or materialtypes. Thus, it is expected that the desired material qualities and/orthe specific type of part being manufactured may dictate whether one,two, three or more different material types will be chosen/required formaking a specific part.

Each of the nozzles 12-16 includes an associated reservoir (not shown)where a specific solution is contained that is deposited through itsassociated nozzle 12-16. Operation of the deposition of the solutionfrom each nozzle 12-16 may be controlled by a processor 18 by openingand closing suitable valves associated with the nozzles 12-16. Theprocessor 18 may also control a suitable heat source 20 for melting theparticles of powdered material 22 a-22 c in each of the solutions 12a-16 a after each is deposited on a substrate. The heat source 20 maycomprise any device suitable for providing the required heat to melt theparticles 22 a-22 c. For example, the heat source 20 may be formed by alaser or a laser diode light source. A high powered laser diode systemthat may be suitable for use in forming the system 10 is disclosed inco-pending U.S. patent application Ser. No. 13/785,484, filed Mar. 5,2013 (U.S. Pub. No. 2014/0252687), and assigned to Lawrence LivermoreSecurity LLC, the teachings of which are hereby incorporated byreference into the present disclosure.

The processor 18 may include suitable software 18 a which includesinformation stored in a non-volatile memory, for example a lookup tablestored in non-volatile random access memory, on specific temperaturesand/or durations that need to be delivered to melt the particles ofpowdered material 22 a-22 c in each solution 12 a-16 a. As such, thedelivery of optical power can be specifically “tuned” to the specifictypes of particles mixed into each of the solutions 12 a-16 a in orderto melt the different types of particles within a determined time frame.The solutions 12 a-16 a in FIG. 1 may have the particles of powderedmaterial 22 a, 22 b and 22 c, respectively, suspended in volatilecomponents 24 a, 24 b and 24 c, respectively. The volatile components 24a-24 c each act as a carrier fluid. The volatile components 24 a-24 cmay comprise, for example, methanol, ethanol, acetone or any othersuitable fluid capable of using latent heat of vaporization for coolingpurposes.

Each solution 12 a-12 c is applied to a substrate 26 (or to a previouslyformed material layer) while the solution 24 a-24 c is at, or nearly at,its boiling point. As a result of the latent heat of vaporization, thevolatile component 24 a-24 c of each solution 12 a-12 c then evaporates,leaving just the previously suspended particles of powdered material 22a-22 b on the substrate 26 (or previously formed material layer) in thedesired configuration. Importantly, the latent heat of evaporationeffectively helps to cool the surface, that is either the substrate 26or the surface of the previously formed layer(s), in the process.

Similar to how an inkjet printer delivers multi-colored ink, the system10 is able to deliver multiple types of powdered materials. The powderlayer remaining after the volatile component 24 a-24 c of each solution12 a-12 c evaporates may be melted with the heat source 20 using apredetermined amount of energy selected for the specific type ofpowdered material. Thus, different types of particles of powderedmaterial may have different amounts/levels of heat used to accomplishthe melting of the particles thereof. The next layer of solution 12 a-12c can then be deposited onto the surface of the just-formed layer andthe material powder 22 a-22 b subsequently melted using the heat source20. The evaporative cooling caused by the latent heat of vaporization ofthe volatile component 24 a-24 c of each solution 12 a-12 c keeps thesurface of the previously formed material layer, and thus the part thatis being produced, at a relatively constant temperature. This is animportant benefit because it helps to maintain the entire part at anacceptable temperature as one layer after another of the part is builtup using the system 10. As AM processes increase in speed in the yearsto come, the waste process heat might be such that the manufacturingprocess will need to periodically stop to give the part time to cooldown. This technique would eliminate that need.

A particularly significant advantage of the system 10 is that it enablesthe manufacturing of parts containing many different materials to befabricated in a single layer at once, or substantially at once. Thus, asan example, portions of a part that may require additional strength maybe formed from one or more types of powdered material while otherportions of the part requiring less strength can be formed usingdifferent types of powdered material. The ability to form a single partfrom a plurality of different powdered materials, and to be able tocontrol where each powdered material is deposited, enables the physicalproperties of the produced part to be closely tailored to meet specificperformance requirements (e.g., durability, longevity, thermaltolerance, stress tolerance, etc.) for the produced part.

The system 10 also enables potentially faster powder deposition overtraditional “sweeping” methods typically employed in an AM process. Insuch traditional methods, typically one raster scan of material is laiddown, with a plurality of scans (sometimes dozens or even hundreds)being required to form a single material layer. The system 10 enablesmultiple materials to be “printed” simultaneously, or virtuallysimultaneously, using the heat source 20 to form an entire layer of thepart at one time or substantially at one time. The ability to cool theunderlying surface on which the newest layer of solution 12 a-12 c hasbeen applied, using the evaporative cooling which results from thelatent heat of vaporization of the volatile components 24 a-24 c, allowscooling to be achieved at those locations on the part where the coolingis needed the most.

While a bed of powder may still be necessary for support, the bed can bemade of materials that are of low cost while high cost materials canstill be used in the layer that form portions of the actual part beingproduced. This eliminates the need to have a powder bed full of thematerial that is to be printed, especially if the printed part is smallrelative to the bed size, the material to be printed is expensive, or ofhigh density. The nozzles 12 a-12 c can be rastered across the powderbed using the processor 18, printing (i.e., depositing) either onlywhere material is desired, or printing material where desired to melt,and using a less expensive or lighter weight filler material everywhereelse. In this regard it will be appreciated that by being able to usedifferent types of powdered materials, the system 10 may potentiallyenable a part to be produced which is lighter than what would otherwisebe the case with an AM formed part made from a single material.

Referring to FIG. 2, a flowchart 100 is presented that provides oneexample of various operations that may be carried out in implementingthe system 10 to make a specific part. At operation 102 the materialreservoir(s) are each loaded with the different types of solutions thathave been selected to make the part. For this example it will be assumedthat a plurality of different solutions 12 a-12 c are being used, witheach solution containing a different type of powdered material 22 a-22 cand a specific volatile component 24 a-24 c, which may be the same orwhich may differ from one another. At operation 104 the processor 18 maybe used to control movement of the nozzles 12-16 to deposit thesolutions 12 a-16 a at specific locations on the substrate 26 while thevolatile components 24 a-24 c of each of the solutions 12 a-16 a are ator near their respective boiling points. The volatile component 24 a-24c of each solution 12 a-16 a will evaporate very rapidly after thesolutions 12 a-16 a are deposited on the substrate 26, typically withina few seconds or less, thus leaving only the powdered materials 22 a-22c.

At operation 106 the heat source 20 may then be used to melt thepowdered materials 22 a-22 c. The melting may be performed across theentire material layer substantially at once, rather than by rasterscanning the heat source 20 back and forth over the substrate 26. Thissignificantly expedites the formation of each layer of the part. As themelting of the powdered materials 22 a-22 c occurs, the particles ofeach type of material are fused together. Thus, any portions wherepowdered materials 22 a remain will be fused into a solid section of thematerial layer, and the same will occur for powdered materials 22 b and22 c.

At operation 108, a check is made by the processor 18 if the entire parthas been completed, and if not, then operations 104-108 are re-performedas many times as needed to form the entire part, layer by layer. Oncethe check at operation 108 indicates that the part is completely formed,the AM process is then complete.

The system 10 and method thus allows for a plurality of powderedmaterials to be deposited, simultaneously, at each layer of a part totailor the use of materials to the physical characteristics that areneeded for the part. The latent heat of vaporization of the fluid alsoenables the part to be maintained at a reasonably consistent temperatureduring the AM process, which would otherwise be difficult or impossibleto achieve with a conventional AM process.

While various embodiments have been described, those skilled in the artwill recognize modifications or variations which might be made withoutdeparting from the present disclosure. The examples illustrate thevarious embodiments and are not intended to limit the presentdisclosure. Therefore, the description and claims should be interpretedliberally with only such limitation as is necessary in view of thepertinent prior art.

What is claimed is:
 1. A method for manufacturing a part via an additivemanufacturing process, the method comprising: forming a solutionincluding a volatile component within which is suspended particles of apowdered material; heating the solution to a temperature at which thevolatile component at least one of begins boiling or is about to beginboiling; performing a material deposition operation by depositing theheated solution at least at one location on a substrate to help form alayer of the part, and allowing the volatile component to evaporate,thus leaving only the particles of powdered material at the onelocation; performing a heating operation using a heat source to heat theparticles of powdered material to a temperature sufficient to melt andfuse the particles of powdered material together; repeating the materialdeposition and heating operations to successively form a plurality oflayers for the part; and wherein the evaporation of the volatilecomponent helps to cool the part.
 2. The method of claim 1, wherein thevolatile component in the solution comprises methanol.
 3. The method ofclaim 1, wherein the volatile component in the solution comprisesacetone.
 4. The method of claim 1, wherein the volatile component in thesolution comprises ethanol.
 5. The method of claim 1, further comprisingforming a plurality of different solutions that include different typesof powdered material.
 6. The method of claim 5, further comprisingtailoring an amount of heat to be applied to each of the different typesof powdered material to accomplish melting of the different types ofpowdered material.
 7. The method of claim 5, further comprising formingthe plurality of different solutions using a plurality of differentvolatile components.
 8. The method of claim 1, wherein the solution isapplied to a plurality of different areas on the substrate, and all ofthe particles of powdered material at the different areas on thesubstrate are heated at one time using the heat source.
 9. A method formanufacturing a part via an additive manufacturing process, the methodcomprising: forming a first solution having a first volatile componentwithin which is suspended a first plurality of particles of powderedmaterial; forming a second solution having a second volatile componentwithin which is suspended a second plurality of particles of powderedmaterial; heating the first and second solutions to temperatures atwhich the first and second volatile components at least one of beginboiling or are about to begin boiling; performing a material depositionoperation by depositing the heated first and second solutions at firstand second different locations on a substrate to help form a layer ofthe part, and allowing the first and second volatile components toevaporate, thus leaving only the first and second pluralities ofparticles of powdered material at the first and second differentlocations; performing a heating operation using a heat source to atleast substantially simultaneously heat the first and second pluralitiesof particles of powdered material to temperatures sufficient to melt andfuse the first plurality of particles of powdered material together, andto fuse the second plurality of particles of powdered material together;repeating the material deposition and heating operations to successivelyform a plurality of layers until the part is fully formed; and whereinthe evaporation of the first and second volatile components helps tocool the part.
 10. The method of claim 9, further comprising tailoringthe heating operation such that a different amount of heat is applied toeach of the first and second pluralities of particles of powderedmaterial to achieve a required melting.
 11. The method of claim 9,wherein at least one of the first and second volatile componentscomprises ethanol.
 12. The method of claim 9, wherein at least one ofthe first and second volatile components comprises acetone.
 13. Themethod of claim 9, wherein at least one of the first and second volatilecomponents comprises methanol.
 14. The method of claim 9, whereindifferent levels of heat are used to heat the first and secondpluralities of particles of powdered material.
 15. The method of claim9, further comprising using a third plurality of particles of powderedmaterial which forms a filler material for the part.
 16. A system formanufacturing a part via an additive manufacturing process, the systemcomprising: a processor; a heated solution including a volatilecomponent within which is suspended particles of a powdered material,the heated solution being heated to a point where the heated solution isat least about to begin boiling; a material deposition componentcontrolled by the processor which deposits the heated solution at leastat one location on a substrate to help form a layer of the part, thevolatile component evaporating after being deposited to leave only theparticles of powdered material at the location; a heat source controlledby the processor to heat the particles of powdered material to atemperature sufficient to melt and fuse the particles of powderedmaterial together; and the processor causing additional depositing andheating operations to be repeatedly performed to successively form aplurality of layers for the part; and wherein the evaporation of thevolatile component helps to cool the part during formation of the part.17. The system of claim 16, further comprising a plurality of materialdeposition components each having a different solution, and wherein theprocessor is configured to control a plurality of deposition devices toselectively deposit the solutions at a plurality of locations on thesubstrate or on a previously formed material layer of the part.
 18. Thesystem of claim 17, wherein the different solutions each includedifferent types of particles of powdered material, and wherein theprocessor is configured to control the heat source to at least one ofsimultaneously or substantially simultaneously heat the different typesof particles of powdered material.
 19. The system of claim 17, whereinthe volatile component of the solution comprises at least one of:methanol, acetone or ethanol.